In the last decade or so, Midwest autumns have become punctuated by more than just falling leaves—they’ve been invaded by swarms of Asian ladybugs. Introduced to prey on crop pests, the native ladybug doppelgägners have become somewhat of a pestilence themselves, coating entire walls of buildings, as they did to one house I lived in during college.

But there’s more to these little red dots than I had given them credit for, as David George Haskell discovered:

These beetles may quite literally have a silver lining. Their ecological success is partly due to their invulnerability to disease, a super-power conferred by their ”hemolymph” (insect blood). The potency of this vital essence is easily confirmed: poke a beetle and see the defensive yellow ooze of blood emerge from chinks in their legs, staining your hand and releasing a powerful odor. Studies of the antimicrobial properties of the blood show that it contains a chemical, harmonine, that inhibits both TB and malaria. Knowing this, I pick the ladybugs out of my hair with new found respect and even a sense of hope that medical wonders may yet emerge from the entomological onslaught.